# Magnon-phonon interactions in magnetic insulators

## TL;DR

This paper develops a theoretical framework for magnon-phonon interactions in magnetic insulators, specifically yttrium iron garnet, analyzing their impact on quasi-particle and transport lifetimes at intermediate temperatures.

## Contribution

It introduces a detailed theoretical analysis of magnon-phonon interactions, including anisotropy- and exchange-mediated mechanisms, and evaluates their effects on magnon transport and damping.

## Key findings

- Phonon scattering has weak effects on magnon transport.
- Magnon transport lifetime differs from quasi-particle lifetime at short wavelengths.
- The study provides insights into magnon damping and transport in yttrium iron garnet.

## Abstract

We address the theory of magnon-phonon interactions and compute the corresponding quasi-particle and transport lifetimes in magnetic insulators with focus on yttrium iron garnet at intermediate temperatures from anisotropy- and exchange-mediated magnon-phonon interactions, the latter being derived from the volume dependence of the Curie temperature. We find in general weak effects of phonon scattering on magnon transport and the Gilbert damping of the macrospin Kittel mode. The magnon transport lifetime differs from the quasi-particle lifetime at shorter wavelengths.